Gustavo vincon



Nov. 8, 1927.

G. vlNoN BREECH CLOSING MECHANISM FOR AUTOMATIC FIREARMS Filed July 15. 1926 Fig. 1

Patented Nov. 8, 1927.

Unir-so srArss GUSTAVO Vinton,

'l or TURIN, rrALY.

y BEISECH-CLQSING IIIECHANSV FOR AUTOMATIC FIB'EABMS.

Application led .Tilly 13, 19,26, Serial No. ,122,138, and in Italy July l5, 1925.

l This invention has for its object certa-n improve-ments in the breech closing mec-hanisni for automatic fire enne having al fixed barrel and a. rotating breech block Where-by a better working and a lQ-llger life of the lire arm and a considerable economy in its construction are obtained.

Said improvements consist Substantially in providing on the head portion of the breech bloelA two retaining shoes provided with 1n` spondingly inclinedV groove provided in the breech bloclr, this latter being thus caused to rotate at a. suitable moment towards its closed position. The plunger is blocked against rotation through a guiding rectilinear ofroove firovided in the cradle in which its shoe slides, and the breech bloc-l: is provided with av lever whereby it is maintained in permanent engagement with the plunger except during the short movement corresponding to the rotation towards the open and` closed position, said lever being automatically disengaged at the beginning vof said movement. r

provided. on the head The invention consists substantially inth lcombi,natiche of the following members:

Shoes for the closure of the breech block portion of the breech block; i

Shoulders for the breech block shoes proyided in a member secured to the cradle, a

plunger (acted upon by a return Spring) .effecting the rotation of the breech blockand Provided to this end with a shoe `guided along a straight line in the cradle and acting through its inclined side on ay correspondingly inclined surface of the breech block, having the purpose of effecting the rot-ation of this latter towards its closed position at the desired moment.

A lever connecting the breech block with the plunger its disengagement being aiutomatically edected throng suitable means secured to the Cradle only during the short movement. corresponding to the rotation o the breech block towards its closed and open position respectively. Y

he following advantages are obtained hy using this invent-ion:

(l) A more satisfactory Working of the lire anni owing to the arrangement of the shoes on' the head portion of the breech block in combination with the lever connecting the breech block With the plunger relieving the rectilinear guide of the plunger shoe from any pressure which, as is well lrnovvn, would Cause a braking of the parte and .e1-possible blocking oft the a-rmdue to a gripping action.

(2) An. easier .and smoother hand arming operation of the breech block due tothe fact that the plunger shoe to he operated' effects only a rectilinear motion,

(3) A considerable economy ofconstruction, as the cradle may he constructed of o rdinary steel requiring'no special treatment as the shoulders on which the breech block shoes act (that must necessarily be of high resistance steel) are obtained in a small detached pieeeand are therefore cheap and ol such forni and size that they will not undergo any permanent deformation during the treatment thus y reducing the losses. Moreover the rectilinear guide of the plunger shoe not being subjected 4to a" noticeable pressureas above stated, the cradle may be constructed of ordina-ry steel.

y (et) long life of the lire arm as the shoulders of the breech block shoes can be replaced while the ,Qlldle lasts longer, having no parts subjected to hard wear.

lThe annexed drawings show by way of example and diagrammatically all improved automatic re arm constructed in accordance i with this invention,

-lligure l is an axial longitudinal section, the breech block being in the open position and the connecting lever being engaged in the plungen Figure 2 is a cross section .on line2-2 0f Ege l. ,i

Figure 3 is a similar ,Section as Figure 1, the breechblock being shown'when starting its movement towards its closed position and the lever connecting same with the plunger being on the point of disengagement.

Figure 4 is a cross section on line 4-4 of Figure 3.

Figure 5 is a similar section as Figures engager.

7' is a detailedviewof the breech mounted inthe casing, is provided at its'- forward end 6 with shoes 7, designed to pass through the slots '3 and engage said inclined shoulders thereby rotating the block for effecting a closure of the latter. rI-'he rear portion of the breeclrblock 5 is formed'with a cylindrical chamber in which is reciprocally .mounted a plunger 12.V This latter is subjected to the action of the return spring 17 and is providedwitli a shoe 11 sliding in a rectilinear guide 10`of the` cradle and passes through an inclined groove 14 of the breech block (Figure 7) in which it is permanently The rectilinear portion 13 of the groove 14 serves only for the mounting of the bolt into the breech block. y

The plunger12 is provided at its head portion with a slot 15 in which the lever 8 of the breech block will engage, said lever being pressed by its spring during the whole rectilinear stroke of thev breech block.

A tooth 9, secured to the cradle in a suitable position, raises automatically the lever v8 from the slotw15 Awhen the breech block is vstarting its'movement towards its closed position and the bolt slot 16' in which said lever lies holds the plungerand the breech blockV disengaged during the whole 'closing or opening action of this latter (Figures 5 and 6)..

The firearm works as follows: When firing, the breech block is caused to rotate by the inclined member attached to the,` cradle, while the plunger which is prevented fromV rotating by` the rectilinear groove 10, is brought backf wards in respect ofthe breech block (Fig- 15 (Figures Gand 2) connectingfthe breech .block and the'plungerpto` each other; theV shoulders 4 of the ures 5 and 1) through the inclined groove 14 breech block 4and bolt, thus connected, will thereupon effectl the recoil stroke, during which the shell is expelled and the feeding forward stroke takes place until the tooth. 9 disengages the lever from the slot 15 of the plunger (Figures 3 and4)l and the kbreech block, disengaged from this latter, rotates towards its closing position (Figures 5 and 6).

On the shoe 11 of the plunger are provided the known means for arming ythe breech block; saidl operation is made easier owing to the fact that the plunger et'fectsonly a rectilinear motion.

Ihat I claim is: Y

1. In an automatic fire-arm the combination of a cradle having inclined shoulders at its forward end, a slidable and rotatable forming a chamber, a plunger slidably mounted in the latter, a spring for pressing the plunger against the bottom of the cham-- ber, a'shoe on the plunger slidable in a reci tilinear guide on the cradle and engaging an inclined groove in the breech-block, means Vfor preventing relative rotation of the breech-block andplunger during the recoil and return motion, and means to release the breech block from the plunger at the end of the rectilinear return stroke for allowing the breech block to rotatev to its closed position. 2. In an automatic firearm the combinal -tion of acradle having inclined shoulders at its Vforward end, a slidable and rotatable breech-block having shoes formed thereon to engage said shoulders, said breech-block having alcylindricalportion on .its rear end forming' chamber, a plunger slidably mounted in the latter, afspring for pressing the plunger against the bottom of the chamber, a shoe on the plungerl slidablein a recvtili'near gui-de on the cradle andengaging an 'inclined groove in the breech-block, a lever on the breech-block having an arm extending into saidchamb'er, to engage the plungerat the end of the rotation of the breecliblock to 'its open position for connecting the breech-block and plunger, and means on the crandle to move' the lever out of engagement with the plunger at thev end of the forward l y f vstrokeof the breech-block to .allow thev latter the end of the rotation of the breech blockl y towards its open position snaps into'the slot -iny invention, I have signed my name.

, GUSTAVO' VINCON. 

